As well as innovative hardware, advanced software and strong strategic partnerships, the area of material development is crucial to the adoption of additive manufacturing (AM).

In the past, vendors focused their efforts on rapid prototyping, the initial mainstay of this technology. The demands here were simple, often only requiring verification and testing. But in recent years, as the demands for realism, fit, functionality and colour grew, so did the application potential.

Now, users are harnessing the technology for the manufacture of complex and tough production tools, factory floor production aids, and even robust, final end-use parts. In many ways, AM materials are the enablers to this, helping to solve the pain points of designers, engineers and manufacturers.

But naturally, each application faces unique challenges, not to mention the complexities and regulatory differences between industries, all of which present a challenge when developing materials.

Healthcare

The healthcare industry is set to spend $1.3 billion on 3D printing in 2018. Today, many hospitals are using 3D printing to enhance patient care and improve surgical practices. Hospitals such as Queen Elizabeth in Birmingham, UK, and the University Hospital Basel, Switzerland, have seen dramatic time and cost-related savings when producing 3D printed medical models using PolyJet technology. With Queen Elizabeth reporting a staggering £20,000 saving per surgery and able to reinvest it into other areas of the hospital, and the University Hospital Basel reducing surgical time by over a third, 3D printing is playing a crucial role in elevating the standard of patient care at both hospitals.

Patient-specific 3D printed models produced today enables surgeons to better visualise the anatomy of interest and practice surgery accurate, patient-specific models. Using advanced colour, multi-material 3D printers, models can be coloured to differentiate critical structures and different materials can be combined for added functionality. This allows physicians to effectively practice, plan and prepare for complex and life-changing surgeries.

However, one of the healthcare industry’s biggest challenges is the need to create models that are not only extremely anatomically realistic, but that respond in a similar way to human tissue. This presents several challenges, from the geometry of the part printed, to the need for multiple, very different materials in a single print. For instance, consider our skin: it is both incredibly soft, yet durable, and 3D printed models need to match this. Every day pioneers are working to find this balance and enable the creation of ultra-precise, anatomically correct, vascular, heart and bone structures that match distinct clinical requirements.

Conversely, some medical practitioners require materials that are more lightweight, durable, or biocompatible, and suitable for long-term contact with the human body. This brings with it many other associated challenges, such as sterilisation and certification.

Aerospace

High-temperatures and challenging regulations don’t just impact the healthcare industry. This is also a huge consideration in the aerospace and rail industry too. By their very nature, these industries have incredibly strict regulations, with parts often needing to withstand gruelling conditions, all while still increasing efficiency, reducing cost and enhancing performance. At the top of every agenda is whether the material meets stringent flame, smoke and toxicity demands, as well as considering heat release and chemical susceptibility. The result is a demand for complex and specific material properties, all of which are required to ensure passenger safety.

Recent media attention has focused on aerospace manufacturers using AM to switch heavier metal parts for strong, lightweight 3D printed thermoplastic alternatives such as Ultem9085, which possesses a high strength-to-weight ratio and is also FST compliant. With this material, combined with hardware solutions developed to address specific industry issues, aerospace organisations can now get more parts certified for flight, much faster.

Automotive

With calls for improved fuel efficiency, ever-present environmental and political pressures, and decentralised production, the drivers in the automotive market are just as tough. Compared to the aerospace industry, the environments are different; where aerospace parts may demand strict flammability requirements, automotive parts need to be crash-safe.

Materials engineers are working towards higher chemical resistance for fuel exposure and optimal combinations of toughness, ductility and stiffness for durability. New materials are opening up new applications in automotive that were previously impossible. 3D printing composite materials, for example, provide the strength of metal, with the light weight of plastic. AM not only offers the option of lightweight parts, but the ability to also optimise performance-to-weight ratios through complex geometric designs with advanced software and hardware capabilities, which cannot be achieved by other methods.

These benefits are underscored by users across the automotive industry and include Formula 1 racing team, McLaren, which operates in the highly-demanding, high-performance world of motorsport. With fused deposition modelling (FDM), McLaren produced a new race-car wing in under two weeks during the last Grand Prix season, using a 3D printed composite mould tool to create the shape of the wing – representing a significant time-saving compared to traditional methods.

“As the industry continues to innovate and meet these needs, the adoption of AM will continue.”

Similarly, Volvo Trucks in France employs is using FDM to design durable yet lightweight clamps, jigs, supports and tool holders for its production facility in Lyon. 3D printing customised tools for direct use on the factory floor, Volvo Trucks estimates that for small quantities of tools, the cost of 3D printing ABS thermoplastic tools can be as little as 1€/cm³, while making the same item from metal costs 100€/cm³. Crucially, Volvo Trucks has reduced the time taken to design and manufacture certain assembly line tools traditionally produced in metal by more than 94%, from 36 days to just two days using FDM AM.

By considering the automotive and aerospace industries, we have identified one of the key issues facing the adoption of AM today. The application focus is constantly shifting from rapid prototyping, to tooling, to final production parts. As this trend continues, we need traceability to guarantee a secure and dependable supply chain.

Where next?

The needs and demands of these industries are not solely driven by material development. Users need to consider the innovations in hardware and software, as well as the knowledge, training and industry specific solutions.

That said, every development is a leap forward for the AM industry. Within design, the greater the ability for a material to match the final end-use part in mechanical, thermal and chemical properties, the greater its likelihood to perform like the final part, and the greater the efficiency of the design process. In production, material properties are crucial to ensure functionality, consistency, surface smoothness, quality and traceability. For this area, material development is a top priority and ongoing challenge, and as the industry continues to innovate and meet these needs, the adoption of AM will continue.